Comparison of Cervical Motor Function between Artificial Cervical Disc Replacement with Prodisc-C and Anterior Cervical Discectomy and Fusion for the Treatment of Cervical Spondylotic Myelopathy

Abstract

Introduction The objective of this study was to compare outcomes of cervical disc replacement (ACDR) using Prodisc-C (Synthes, Inc.) and anterior cervical discectomy and fusion (ACDF) in patients with symptomatic cervical spondylotic myelopathy. Materials and Methods A total of 40 patients with radiologically confirmed symptomatic cervical spondylotic myelopathy were enrolled between March 2008 and August 2011 into prospective ongoing study and received ACDR (N = 20) or ACDF (N = 20) at discretion of operating surgeon. Patients were followed up at pre-specified intervals at 1, 3, 6, 12, and 24 months postoperative. Follow-up evaluations consisted of visual analogue scale (VAS) for neck and arm pain intensity, Neck Disability Index (NDI), and radiologic evaluations of intervertebral disc height, cervical curvature, total cervical range of motion, and segment contribution to total cervical range of motion (ROM). Results Both groups improved in VAS and NDI scores after surgery. The NDI score improved (p < 0.01) from 34.06 preoperative to 16.81 at 24 months in the ACDR group and from 35.60 preoperatively to 17.28 at 24 months in the ACDF group. The difference between the groups was not significant. The VAS for neck and arm pain intensity showed better outcomes in ACDR than in ACDG group at 6 months follow-up (p < 0.05). This difference disappeared at 24 months follow-up. The disk height at the index level increased in both groups postoperatively. There were no changes in disk height at the first cephalic and caudal levels in either group at any follow-up. The total cervical range of motion (ROM) improved at all follow-up evaluations in the ACDR group (p < 0.05). There were no changes in overall ROM in the ACDF group (Fig. 1). The overall ROM was higher at 24 months in ACDR compared with ACDF (49.93 ± 11.91 and 41.11 ± 9.80, respectively, p < 0.05). Conclusion ACDR and ACDF are effective in improving functional outcomes in subjects with symptomatic cervical spondylotic myelopathy. Range of motion outcomes are superior in ACDR compared with ACDF.